#include <iostream>
#include <iomanip>

int main(){

    std::cout << "========bool 类型==========" << std::endl;
    bool isClick = true;
    std::cout << "是否点击了：" << isClick << std::endl;

    std::cout << "========char 类型==========" << std::endl;
    char c = 'a';
    std::cout << "字符是：" << c << std::endl;

    std::cout << "========int 类型==========" << std::endl;
    int age = 20;
    std::cout << "年龄是：" << age << std::endl;


    std::cout << "========long long 类型==========" << std::endl;
    long long visits = 10000000000000;
    std::cout << "访问量是：" << visits << std::endl;


    std::cout << "========float 类型==========" << std::endl;
    float f1 = 3.141592;
    float f2 = 3.141592653f;  
    std::cout << "f1: " << f1 << std::endl;
    std::cout << "f2: " << f2 << std::endl;


    std::cout << "========double 类型==========" << std::endl;
    double d1 = 3.141592653;
    double d2 = 3.141592653589757637;  

    std::cout << std::fixed<<std::setprecision(20)<< "d1: " << d1 << std::endl;
    std::cout <<std::fixed<<std::setprecision(20)<< "d2: " << d2 << std::endl;

    return 0;
}